Pentax Optio V20

Noise – Manual ISO (9.85)
In our core image noise test, we raise the camera ISO manually while keeping illumination unchanged. As you can see in the graph below, the V20 started with a noise level above 1%, quite high at the lowest available ISO settings, and after a brief image-processing-related dip, jumped to about 1.5%, stayed flat briefly, then jumped again at ISO 1600.

The reasonable performance at higher ISOs, where many cameras in this class become aggressively noisy, balances out the somewhat disappointing results in the meat-and-potatoes 400-and-below ISO range to produce an average overall noise score.

Auto Noise (2.38)
Our auto noise test really combines two separate but related camera capabilities. Image noise rises as light sensitivity (measured as ISO setting) rises. In this case, we allow the camera to choose an ISO setting using its automated system to match our well-lit laboratory conditions. A higher-than-necessary ISO will result in a noisier photo, particularly in a camera that suffers from less-than-impressive noise performance in the first place. For the Optio V20, the camera chose to shoot at ISO 250, significantly but not radically higher than necessary, resulting in a mediocre score.

Low Light (5.32)
We're grateful to have a flash available when it's the only way to get a shot, but we'd prefer to keep it from firing and shoot using available light whenever possible. To make flash-free shooting feasible, though, requires  the camera to keep image noise and color accuracy under control with the lights down low, a difficult assignment. To test a camera's success here, we shoot our color chart with the camera's ISO setting cranked up to a very sensitive 1600, using four light levels, ranging from the 60-lux setting that roughly matches restrained household lighting to the 5-lux illumination that's about what a single candle throws off.

Low Light Tests
60 Lux	30 Lux
15 Lux	5 Lux

As shown in the Imatest results above, the V20 hangs in pretty well on both color and noise as the lighting drifts down to 15 lux, then just throws in the towel as we get down to 5 lux. Since the four light level results are averaged to produce a final score, the fact that performance doesn't taper off but instead falls off a cliff definitely hurt the V20's numbers here. Under more common lighting conditions, the camera performed reasonably well.

Our low-light inquisition includes a second test designed to assess long exposure performance. Unlike a sophisticated SLR, where you can manually set the shutter speed and produce low-light, long-exposure images ranging to 30 seconds and beyond, our point-and-shoot friends need to be coaxed into allowing more than 60 seconds' worth of light to enter their innards. In this case, using the night scene mode, we shot at 2.5 and 3 seconds, at ISO 400, and found the resulting images maintained decent color accuracy with passable image noise levels.

Combining the two low-light testing results into an overall score puts the V20 squarely in the pack of contenders, where the lack of variation is more noteworthy than the slight statistical differences.

Pentax V20 Low Light Scores

Still Life
Providing a basis for comparing a single camera's image quality as ISO settings escalate, or to compare and contrast performance at a range of ISO settings between cameras, we shoot the same two still life setups for each review, under standard fluorescent lighting and with the camera set for automatic exposure. The full-size originals are available by clicking the thumbnails below, with the caveat that these are large files and may take some time to download if your Internet connection is less than robust. 

ISO 80
ISO 100
ISO 200
ISO 400
ISO 800
ISO 1600

Video Performance (6.96)
Where once we were grateful to have a camera that could turn out decent stills, today we expect these digital devices to expand their repertoire and serve our cinematic needs as well. To test their success in this regard, we begin by shooting video of our color chart under both bright and dim lighting conditions, grabbing still frames from these videos, then analyzing the color and noise results for each and generating comparative scores against other models.

Low Light - 30 Lux
Turn down the lights to the level where your friends are more likely to act foolish enough to provide decent YouTube fodder and color accuracy drifts pretty much across the board, but not anywhere near as badly as we often see in this class of camera, and flesh tone reproduction is still exceptionally good.

Resolution (1.66)

We test video resolution by shooting our image chart under bright lights and, again, evaluating still frame captures using Imatest. This is a tough test when shooting at 640 x 480 resolution, and the V20 performance is borderline acceptable at a maximum 400 lw/ph horizontally and 355 lw/ph vertically.

Motion (1.5)

To move beyond the on-a-tripod testing of resolution and color accuracy we take to the streets, recording speeding autos and evaluating the blur, smoothness and level of detail in the resulting video. The Optio V20 handled this test well, with no evident motion faults, though without a lot of detail.

Taking the battery of video tests together provides an overall score of 6.96, which compares favorably with the other cameras in our comparison suite. Still not exactly the gear we'd recommend for your shot at Sundance fame and fortune, but a notably better-than-average choice for quick clips and video captures.

Pentax V20 Video Scores